Blast wave propagation in rock mass—Part I: monolithic medium

This contribution presents an introduction into that part of the field of elastic wave propagation which is relevant to blasting of single and multiple boreholes and addresses briefly borehole breakdown and the formation of the fracture network around a borehole which ultimately leads to the disintegration of the rock mass. Phenomena of this kind are encountered in mining and quarrying. Analytical as well as numerical work referring to stress wave expansion from a detonating borehole will be addressed in detail. Much of the research reported here has been performed at the Fracture and Photo-Mechanics Laboratory (FPML) at the Vienna University of Technology. In order to gain an improved understanding of the mechanisms controlling borehole breakdown and ensuing rock fragmentation, a multidisciplinary approach is followed which includes analytical work and numerical modeling. The main emphasis is put on the effect of the velocity of detonation on the stress wave propagation and interaction with the rock mass which may contain a variety of special features such as layers, delaminations, faults and other geological structural discontinuities. This paper consists of two parts, and describes the results of numerical simulations demonstrating the applicability of the dynamic finite difference program SWIFD. The following topics will be discussed in each part: in Part I (this article), blast wave propagation in monolithic rock; in Part II, the interaction between stress waves and geological features of discontinuity such as interfaces, cracks and faults.